title: Dynamic helical CT of the abdomen: prospective comparison of pre- and postprandial contrast enhancement.
abstract: OBJECTIVE
  To investigate effects of a liquid meal on contrast material enhancement at dynamic helical computed tomography (CT).
  
  
  METHODS
  Twenty healthy, fasting subjects underwent intravenous injection of nonionic contrast material at 4 mL/sec. Axial CT sections were obtained at a single level 15 seconds after injection, then every 5 seconds for 2 minutes. This protocol was repeated 1 week later, after ingestion of a 360-calorie liquid meal. Hepatic, splenic, and aortic attenuation were measured before and after contrast material administration. Peak enhancement level, time to peak enhancement, slope of hepatic enhancement, and hepatic, splenic, and aortic enhancement ratios were determined.
  
  
  RESULTS
  Postprandial time to peak enhancement was 4.4 seconds earlier than preprandial (59.6 seconds +/- 9.0 [1 standard deviation] vs 64.0 seconds +/- 9.5; P < .02). No differences in maximum attenuation were found (P > .27). Postprandial maximum slope of hepatic enhancement and temporal and quantitative enhancement characteristics in aorta and spleen did not significantly differ. Postprandial hepatic-to-splenic enhancement ratios increased (P = .04), and aortic-to-hepatic ratios decreased (P = .01). Aortic-to-splenic ratios did not differ (P = .45).
  
  
  CONCLUSIONS
  A liquid meal before intravenous injection of contrast material produces more rapid peak hepatic enhancement, with slightly increased relative hepatic enhancement. A patient's dietary status, however, should not influence the CT protocol.
authors.affiliation: Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: D H
authors.initials: DH
authors.lastname: Sheafor
authors.forename: M T
authors.initials: MT
authors.lastname: Keogan
authors.forename: D M
authors.initials: DM
authors.lastname: DeLong
authors.forename: R C
authors.initials: RC
authors.lastname: Nelson
mesh_terms: D000328:Adult; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging; D003287:Contrast Media; D019422:Dietary Sucrose; D005260:Female; D005526:Food, Formulated; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007479:Iopamidol; D008099:Liver / Q000000981:diagnostic imaging*; D008297:Male; D019518:Postprandial Period; D011446:Prospective Studies; D013154:Spleen / Q000000981:diagnostic imaging; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D019422:Dietary Sucrose; C082131:Ensure formulated food; D007479:Iopamidol